Mark Furler is APN Australian Regional Media’s group digital editor. He’s an award-winning journalist who has lived and worked on Queensland’s Sunshine Coast for more than 25 years. He’s passionate about fighting for a better go for locals. His awards include APN Editor of the Year, and involvement in three PANPA Newspaper of the Year wins for the Sunshine Coast Daily.

iPhone X's TrueDepth camera captures accurate face data by projecting and analysing more than 30,000 invisible dots to create a depth map of your face. It also captures an infrared image of your face.

"A portion of the A11 Bionic chip's neural engine - protected within the Secure Enclave - transforms the depth map and infrared image into a mathematical representation and compares that representation to the enrolled facial data,'' Apple says in a statement on the technology.

"If there is a more significant change in your appearance, like shaving a full beard, Face ID confirms your identity by using your passcode before it updates your face data."

It is designed to work with hats, scarves, glasses, contact lenses, and most sunglasses, even in total darkness.

We've been using Face ID for the past few days and it works very quickly.

I wear glasses - something that proved a stumbling block to facial recognition on Samsung's flagship Note8 - to the point where I gave up.

The first buyer of an iPhone X, Mazen Kourouche, took a selfie inside the Apple store in Sydney this morning (Picture: Saeed Khan/AFP).

In contrast, Apple's Face ID works very well - including when making purchases at stores using Apple Pay.

The only issue is if you are too far away from your phone.

Apple says it works best when the device is arm's length or less from your face (25-50 cm away from your face).

The tech giant also points out that the data that makes Face ID work always remains on your phone, is encrypted and protected with a key available only to the Secure Enclave.

It is not shared to Apple's servers or used to match other data from your phone.

iPhone X launched:
Ten years after the first iPhone Apple launches iPhone X.

So can't someone just use your face or a photo to unlock your phone?

Apple says Face ID uses far more detailed information than that found in a print or even a 2D digital photograph.

"Face ID is even attention-aware. It recognises if your eyes are open and looking towards the device. This makes it more difficult for someone to unlock your iPhone without your knowledge (such as when you are sleeping)."

There are also other safeguards, including the use of your passcode.

That has to be used when:

• The device has just been turned on or restarted.
• The device hasn't been unlocked for more than 48 hours.
• The passcode hasn't been used to unlock the device in the last six and a half days and Face ID hasn't unlocked the device in the last 4 hours.
• The device has received a remote lock command.
• After five unsuccessful attempts to match a face.
• After initiating power off/Emergency SOS by pressing and holding either volume button and the side button simultaneously for 2 seconds.